Piston



Feb. 9 1926. 1,572,325

I w. E. SMlTH PISTON File p 15. 1925 2 Sheets-Sheet 1 Patented Feb. 9,1925.

UNITED STATES WILLIAM. E. SMITH, OF JACKSON, MISSISSIPPI.

PISTON.

Application filed September To all whom it may concern.

Be it knownthat I, \VILLIAM E. SMITH, a citizen of the United States,residing at Jackson, in the county of Hinds and State of hztississippi,have invented certain new and useful Improvements in Pistons, of whichthe following is a specification.

The present invention relates to internal Combustion engines, and moreparticularly to the construction of pistons for use in. the same. I

An object of the present invention is to provide a piston which iscapable of being expanded to approximately sixty-one-thousandth of aninch for taking up wear be tween the cylinder wall and the piston inlieu of discarding the worn piston and substituting a piston of largersize as is now the custom.

Another object of the invention is to provide a piston with anexpansible skirt so connected to a piston head that the skirt may beexpanded to take up wear without interfering with the head and pistonrings and to provide a skirt which may be made 'relatively light and atthe same time strong and durable. y

The invention further aims to provide a novel connecting rod mounting inthe piston for supporting the piston pin adjustably to take up wearbetween the same and its seat or support so that both the piston and"the 'pin may from time to time be adjusted 'to compensate for wear sothat the piston and the pin may last throughout the life of the motor.

The invention still further provides a piston head and a piston skirtwith novel means for connecting the same rigidly together and whichadmits of the adjustment or expansionof the skirt without weakening theconnection, the connection also serving-to rigidly hold the skirt in itsexpanded position. p j

The above and various other objects and advantages of this-inventionwill in part be 'describedin and in part be understood from thefollowing detailed description of the present preferred embodiment,- thesame-be ing illustrated in the accompanying draw ings, wherein;

Fig. 1 is a, longitudinal vertical section through an enginecylindershowing in side (elevation a piston constructed according to thepresent invention mounted therein. i Fig. "2 an enlarged longitudinal.section head 11. The webs 16 have an inner nunib er -of machine screws18' or the like "whih pass" through elongated openings 1?) 15, 1925.sci-m1 No. 56,522.

taken through the piston on the line 22 of Fig; 1. Y

Fig. 3 is a transverse section taken through the piston on the line 33of Fig. 2. 6 Fig 4 is a bottom plan view of the piston with theconnecting rod mounted therein,

the latter being shown in section. V

Fig. 5 is a detailside elevation of the piston head with the connectingrod bearing mounted thereon. v

Fig. 6 is a fragmentary enlarged section taken through one side of thepiston substantially on the line 66 of Fig. 4.

Fig. 7 is a detail inner face view of the bearing cap for the pistonpin.

Fig. 8 is a detail bottom plan or end view of the piston skirt, showingthe two halves separated.

Fig. 9 is an enlarged fragmentary sec tion through one side of thepiston substantially on the line 99 of Fig. 4, and

Fig. 10 is a plan view of one of the filler plates employed between thehead and skirt of the piston.

Referring to the drawings 10 designates the cylinder of an internalcombustion engine of any suitable type and in which the improved pistonmay be mounted. The piston comprises a head 11 equipped with the usualcompression rings 12 adapted to seal the head in the cylinder 10, andthe head 11 carries a two part skirt 13 and 14 and is secured to theupper or outer end of a connecting rod 15. I

The head 11 is preferably solid and of substantial thickness or lengthto carry the rings 12 and give the desired Weight to the piston. Theskirt comprises a pair of semicylindrical sections 13 and 14 which areprovided at their upper ends with inwardly extending webs 16 partiallyclosing the upper end of the skirt and adapted to engage flat againstthe lower side of the marginal configuration providing a substantiallyrectangular opening 17" through the top of the skirt for a purposewhichfwill presently appear, and the ends of the webs 16 and'thecylinder skirt sections 13 and 14.1

"terminate 'infiatopposed faces adapted to 'be brought' together whenthe skirt is assembled asshown in Fig. 3 to complete the cylindricalformation.

The skirt; is secured to the head by "ii- 10 a general direction ofseparation of the skirt sections 13 and let to admit of the expansion ofthe skirt by merely loosening the screws 18. In the present instanceeight screws 18 are employed but any suitable number may be useddepending upon the size and character of the piston, and the conditionsof manufacture and use.

At their meeting ends. the skirt sections 13 and ll are provided withoverlapping tongues 20. one on one end of each skirt sectioin whichslid-ably engage in depressions or seats 21 formed in the opposite endsof the skirt sections 13 and 14:. From Fig. 1 in particular the tongues20 may' be relatively short and the seats 21 correspondingly formed soas to-provide shoulders -tor maintaining the skirt sections 13 and 14against lengthwise displacement.

The meeting ends of the skirt sections 13 and l l are also recessed asat -55 to provide bolt openings to receive expansion bolts 24, onebetween each pair of ends ot'the sections. From Fig. 2 it will be notedthat each bolt 24: is provided with a taper-inf: shoulder at its innerend and a second tapering shoulder 26' near its outer end; The boltopenings 23 are similarly provided with cam surfaces 27 and 28respectively at the lower and u 'iper ends of the skirt to receive theshoulders and thereaeainst when the screw 21- is turned upwardly fort-rpandhu: the skirt sections 13 and Mimitornily at the bottom and topof the shirt.

The free ends of the bolts are threaded and engaged in threaded openingsformed in the lower side of the head 11. the threadet portions of thebolts being of suflieient length to support thesame and maintain thebolts in adjusted position. The screws 18 are depended upon to firmlyhold the skirt to the head, and. the elongated openings 19 admit of theadjustment of the skirt without requiring removal or displacement of thebolts 18. i

For the purpose of closing and sealing the joint at the upper ends ofthe skirt sec tions 13 and 14,1)ackii1g plates 29, are employed and maybe constructed as shown in detail in Fig. 10 with an intermediateopening 30 for the reception of the upper threaded ends of the bolts"24, the outer marginal edges 31 of the plates 29 co-nforn'iing to thegeneral curvature of the meeting ends of the skirt sections. The inneredges 32 ot theplates are preferably straight so as to lie within theinar inal edge portions of the webs 16. The ends of the plates 29 arepreferably bevelled so as to remain out of contact with the adjacentscrews or bolts 18.-

The skirt sections 13 are reinforced at suitable points enlargements :84on their niner slde's, such enlargements being preferably formedintermediate the ends of the skirt sections and also at the meeting endsthereof. The enlargements extend longitudinally ot' the skirt andreinforce and strengthen thesanie against cracking.

The piston is provided with a novel type of connecting rod hearing whichcomprises a bearing block 35 which has an upper flat tace adapted toseat against the lower side of the piston head 11 and which is of a configuration to extend downwardly through the opening 17 in the top of theskirt. The block 35 is provided with an elongated central depression 36adapted to receive the up per part of a ball head carried upon the upperend of the connecting rod 15. At opposite ends oi the depression 36, theblock 35 is provided with cylindrical pin bearing surfaces 38 adapted toreceive the upper side 01? a piston pin 39 at opposite ends, The pin 39is carried through the head 37, and

the pin and the head are held to the blocl;

no by a cap plate 40 which is secured against the lower side of theblock 35. The cap plate 40' is provided with cylindrical hearingportions 41 at opposite ends adapted to engage the lower side of the pin39 while the intermediate portion of the block 4-0 is recessed or opento leave free the lower side ofthe'ball head 37, and to receive the conenectinp; rod 15 therethroug'h.

Screw bolts 42 or the like are secured through the corner portions ofthe capplate -10 and the block 35, and pass upwardly into the head 11for securing the connecting rod bearing directly to the head andindepend ently (it the skirt. By this construction the skirt is relievedoi? all strain usually imposed upon the skirt by the piston pin and itsbearings. A plurality of shims are interposed between the opposite sidepoi-' tions of the block 35 and cap plate 40, and may be individuallystripped off to take up wear which may occur between the piston pin. 39and its bearings 38 and ll.

The piston and connecting rod are operated in the usual manner. andafter considerable wear has taken place between the cylinder and piston,and between the connecting rod and its bearing, instead ofdis cardingthe plston and piston pin for new ones or larger dimensions, the pistonmay be enlarged by loosening the bolts 18, turning up the expansionbolts 244.0 spread the skirt sections 13 and 14, and again tighteningthe bolts 18. One or more shims 1'3 may be removed "from between theblock 35iand the cap plate 4O 01" the piston pin bearing to take up lostmotion between the same. With these adjustments the piston and pistonpin may again be used and similarly adjusted from time to timethroughoutthe life of the" engine. I v

It is elt course understood that various changes and inod fif ea be ndethe details of construction and design of the above specificallydescribed embodiment of this invention without departing from the spiritthereof, such changes and modifications being restricted only by thescope of the following claims.

What is claimed is:

1. A piston comprising a head, a pair of skirt sections detachablymounted on the head, means for locking said skirt sections togetheragainst vertical movement at their abutting edges, and a pair ofexpanding bolts adapted to extend through said skirt sections at theabutting edges thereof.

'2. A piston comprising a head, a pair of independent and detachableskirt sections carried by the head, each of said skirt sections havingrecesses in one edge intermediate thetop and bottom thereof and ashoulder at the opposite edge, said shoulder of one section beingadapted to seat in the recess of the other section for locking thesections against vertical movement, and a pair of expanding boltsadapted to extend through said skirt sections adjacent the abuttingedges thereof.

3. A piston comprising a head, a pair of skirt sections independentlyand adjustably secured to the head, and a pair of expanding boltscarried by the head and engaging between the abutting ends of the skirtsections. '7

4:. A piston comprising'a head, a pair of skirt sections having inwardlyextending webs at their upper ends, bolts extending through the webs andinto the head for securing the webs thereto, and a. pair of expandingbolts threaded in the head and lying between the abutting ends of theskirt sections for expanding the same.

5. A piston comprising a head, a pair of skirt sections having inwardlyextending webs at their upper ends adapted to engage the lower side ofthe head and having openings therethrough elongated inthe direction ofseparation of the sections, bolts engaging through the openings andsecured in the 7 head for binding the skirt sections'thereto whenadjusted, and expansion bolts extending upwardly between the abuttingends of the skirt sections and threaded in the head for advancing thebolts upwardly when turned, said bolts having inclined shoulders thereonand said skirt sections having cam surfaces engagin the shoulders of thebolts for expanding the'skirt sections when the bolts are turned up. i

6. A piston comprising a head, a pair of skirt sections, means forindependently and adjustably securing the skirt sections to the head,expansion bolts extending between the adjacent ends of the skirtsections and threaded in the head, inclined shoulders on said bolts atthe upper and] lower ends there of, and cams on the upper and lower edgeportions of the skirt sections engaging said shoulders for uniformlyexpanding the upper and lower portions of the skirt when the bolts areturned.

7. A piston comprising a head, a skirt detachably secured to the lowerside of the head and having an opening in its upper end, a bearing blockengaging the lower side of the head and extending through said I openinginto the skirt, said block having a central depression and bearingsurfaces at opposite ends of the depression, a connecting rod having aball head adapted to seat in said depression, a piston pin carriedthrough the ball head and engaging at opposite ends in said bearingsurfaces of the block, a cap plate engaging against the lower side ofthe block having a central opening for said ball head and the connectingrod and provided with bearing portions at opposite ends to 'engage saidpin and hold it to the block,

and screw bolts extending upwardly through the cap plate and block and:into the piston head for holding the block'and cap plate thereto.

WILLIAM E. SMITH.

